Optical module device driven by a single power supply

Abstract

An optical integrated circuit having optical devices is fabricated. These optical devices must be biased in the mutually opposite directions. If such an optical integrated circuit is fabricated using a conductive semiconductor substrate as conventionally, it is not possible to drive the devices by a single power supply since the substrate side is shared as a common polarity by the devices. The present invention realizes a structure where both anode and cathode of each device can be isolated electrically by conventional process technology and provides an optical integrated circuit which can be driven by a single power supply. An optical integrated circuit is formed on a semi-insulative or insulative substrate. A high resistivity region which extends at least from the active layer to the substrate and includes part of an optical waveguide between the devices is formed so as to electrically isolate the anode and cathode of each integrated device from the other device.

1. An optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising:
 an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; 
 a second layer including an active layer formed on the substrate or the first layer; 
 an optical waveguide which is formed on the second layer so as to optically couple with the other device; and 
 a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device, wherein the high-resistivity isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer. 
 
     
     
       2. An optical integrated circuit which is driven by a single power supply according to  claim 1 , wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated. 
     
     
       3. An optical integrated circuit which is driven by a single power supply according to  claim 1 , wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated. 
     
     
       4. An optical integrated circuit which is driven by a single power supply according to  claim 1 , wherein cladding layers which sandwich a core layer forming the optical waveguide are shared by each of said devices. 
     
     
       5. An optical integrated circuit which is driven by a single power supply according to  claim 4 , wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated. 
     
     
       6. An optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device, wherein the high-resistivity isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer. 
     
     
       7. An optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device, wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated, and the high-resistivity isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer. 
     
     
       8. An optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device wherein the isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer and wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated. 
     
     
       9. An optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device wherein cladding layers which sandwich a core layer forming the optical waveguide are shared by each of said devices and wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated, and the high-resistivity isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer. 
     
     
       10. An optical communication system unit using the optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device, wherein the high-resistivity isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer. 
     
     
       11. An optical communication system unit using the optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device, wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated, and the high-resistivity isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer. 
     
     
       12. An optical communication system unit using the optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device wherein the isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer and wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated. 
     
     
       13. An optical communication system unit using the optical transmission module using the optical integrated circuit which is driven by a single power supply, said optical integrated circuit including at least two devices which are biased in the mutually opposite directions, each of said devices comprising: an electrically semi-insulative or insulative substrate or an electrically semi-insulative or insulative first layer; a second layer including an active layer formed on the substrate or the first layer; an optical waveguide which is formed on the second layer so as to optically couple with the other device; and a selectively formed high-resistivity isolation region which partly includes the optical waveguide and the active layer and extends to at least the substrate or the first layer so that each of an anode and cathode of the device is electrically isolated from the other device wherein cladding layers which sandwich a core layer forming the optical waveguide are shared by each of said devices and wherein at least two of a semiconductor, an optical modulator, an optical amplifier and an optical detector are integrated, wherein the high-resistivity isolation region is formed by an epitaxially-grown semi-insulative semiconductor layer. 
     
     
       14. A method for manufacturing an optical integrated circuit which is driven by a single power supply, the manufacturing method including the steps of:
 preparing an electrically semi-insulative or insulative substrate; 
 forming a stacked layer on the substrate where an optical guide layer, first contact layer, an active layer, a second guide layer, a cladding layer, and a second contact layer are deposited in this order; 
 selectively etching the stacked layer so as to extend to the substrate; 
 epitaxially growing a semi-insulative semiconductor layer on the selectively etched region; and 
 forming a electrode for the device after selectively etching a passivation film being deposited on the stacked layer. 
 
     
     
       15. A method for manufacturing an optical integrated circuit which is driven by a single power supply, the manufacturing method including the steps of:
 preparing an electrically semi-insulative or insulative first layer being formed on a conductive substrate; 
 forming a stacked layer on the first layer where an optical guide layer, first contact layer, an active layer, a second guide layer, a cladding layer, and a second contact layer are deposited in this order; 
 selectively etching the stacked layer being extended to the first layer; and 
 epitaxially growing a semi-insulative semiconductor layer on the selectively etched region.